A gene therapy approach for treating T-cell–mediated autoimmune diseases

Abstract

Experimental autoimmune encephalomyelitis (EAE) is a demyelinating disease of the central nervous system (CNS) that serves as a model for multiple sclerosis (MS) in humans. In mice, EAE is mediated by Th1 type CD4(+) T cells specific for various myelin proteins which migrate from the periphery to the CNS. Removal or blocking of CD4(+) cells before or shortly after disease induction was shown to prevent disease onset and/or disease progression but also results in general immune suppression. Most treatment regimens for autoimmune diseases currently rely on general suppression of the T-cell compartment most commonly by steroids. In this paper, an experimental, gene therapy-based model is presented in which susceptible mice are made resistant to EAE induction by specifically down-regulating an autoreactive T-cell population. By using a retroviral gene transfer protocol, normal B cells were genetically modified to constitutively express the SJL-specific proteolipid (PLP) encephalitogenic determinant and then adoptively transferred into syngeneic hosts. To ensure appropriate presentation of the exogenous encephalitogenic peptide in association with MHC class II, the encephalitogenic sequence was fused to a lysosomal targeting sequence. Adoptive transfer of syngeneic B cells expressing the PLP encephalitogenic determinant into normal, naive, genetically susceptible mice induced PLP-specific unresponsiveness and completely protected the majority (62% and 83% using an intermediate and a high titer retroviral vector, respectively) of the animals from EAE induction. The remaining animals had a delayed disease onset and/or lower disease severity. All protected mice expressed the exogenous gene in the spleen as detected by reverse transcriptase-polymerase chain reaction.

Viral DNA tethering domains complement replication-defective mutations in the p12 protein of MuLV Gag

“…Factors that could alter the transport of the PIC to the nucleus did not overcome the p12-PM14 defect. Insertion of nuclear localization sequences (NLS), including the classical SV40 T antigen (TAg) NLS and the nonclassical KSHV LANA NLS (LANA [24][25][26][27][28][29][30][31][32] ), did not rescue MuLV p12-PM14, and neither showed tethering to the mitotic chromatin (Fig. S2).…”

Gene therapy in autoimmune, demyelinating disease of the central nervous system

“…Gene therapy has not yet been attempted in MS, but there have been a number of studies in EAE that have invariably shown some level of efficacy at inhibiting the disease (Table 1), although in many cases this has only been an amelioration rather than elimination of disease. As the majority of the CNS is postmitotic, this puts constraints on the nature of the vector that can be used, and to date administration of plasmid DNA, [32][33][34][35][36][37][38][39][40][41] viral infection, [42][43][44][45][46][47][48][49][50][51][52][53] and retrovirally transduced cell (RVC)-carriers 47,[54][55][56][57][58][59][60][61][62][63] have been investigated in EAE (Table 1). These have largely focused on inhibition of the immune response either applied centrally to target the local pathological events within the CNS or peripherally administered to inhibit: initial sensitization, the activities of circulating cells or perivascular events in areas of local BBB breakdown.…”

“…89 A number of approaches aimed at preventing the generation of encephalitogenic T cells have been assessed (Table 1). 32,[36][37][38]40,62,63 In some EAE models such as the PL/J mouse and Lewis rat, the disease is caused by activity of cells with very limited T-cell receptor (Tcr) subtype heterogeneity. Here, the majority of encephalitogenic cells express TcrVb8 90 and prophylactic, systemic DNA vaccination against this Tcr subtype has induced EAE amelioration.…”

“…[36][37][38]62,63 This approach should offer the most specific form of therapy and thus limit potential side effects. This has been shown to be active in disease, either as a secreted fusion protein 62,63 or DNA vaccination, [36][37][38]40 induced with all of the three major encephalitogenic myelin proteins (Table 1). In EAE it is clear that different strains respond to different peptide epitopes because of the restrictions imposed by the MHC haplotype(s) expressed, and the pathogenic T-cell repertoire expands with disease progression.…”

Vectors for the treatment of autoimmune disease

“…78 Collagen II-specific T-cell hybridomas modified to express an IL-12 antagonist were capable of ameliorating CIA. 79 Adoptive transfer of syngeneic B cells, transduced by fusion genes of autoantigens with IgG1 H chain, 80 or with lysosome-targeting Lamp-1 signal, 81 prevent and even cure animal models of diabetes and MS. Fibroblasts and arthritogenic splenocytes transduced to express soluble complement receptor 1 were therapeutic in mouse CIA. 82 Indeed, ex vivo retroviral strategies have already entered the clinic.…”